"Simply take your favorite TTF font and make two copies of it, named as follows:

SCE-PS3-SR-R-LATIN
SCE-PS3-SR-R-LATIN2

And place these on your PlayStation 3 flash in the directory, /dev_flash/data/font/ overwriting the original fonts, then you simply need to go to theme settings and change the font to either rounded or pop to enjoy your new system font!"